Seafrogs ST-100 Pro Underwater strobe - need your openion

I just ran another test - dark room, camera set to ISO 100, f/22, 5 seconds exposure, +3 flash compensation. Triggering the strobe via on-camera flash produced an underexposed image, but triggering it with my cellphone's LED flash (that's what the five second exposure is for - open the camera shutter, then trigger the ST-100 by taking a forced-flash photo on the phone with the fiber optic held up to its flash LED) produced a noticeably brighter exposure. While I can't quantify it, this does confirm that the strobe's maximum power output is held back by the triggering bulb's pulse duration.

I have contacted Meikon support, and they have offered to replace the strobes, but right now I don't see the point of shipping them back and forth again as with six different strobes exhibiting the same behavior, this appears to be a design issue rather than a manufacturing defect. I have explained the problem, linking your video and davec13o2's oscilloscope results as additional proof - let's see what they have to say. Maybe a miracle happens and they redesign the optical trigger circuit and replace all of our strobes? I know that an early batch of A6xxx Salted Line housings had an issue where they leaked between 5 and 10 meters, and they replaced those quickly and at no cost.

Looks like they have disappeared from Sea Frogs and Meikon websites. When you consider how much you might spend to get to a remote divesite the extra cost for a proven item seems fairly minimal at least to me. If your budget is limited and you don't want to be a Beta tester then the little INON S2000 at $365 in the USA at any rate seems like a good deal, you give up a little power it's guide number 20 at 100° coverage. The S&S YS-2J seems a lot better at 32, but it comes back to 24 guide number with the diffuser required to get 100° coverage, so you lose about 1/2 stop to the YS-2J.

Indeed; well spotted. It's odd that it has taken so long for someone to report these issues - ST-100 has been available since late last year, and in fact this is already the second iteration of the product; before the maroon-colored ST-100 Pro, there was a black-colored ST-100 - I wonder what caused that replacement. I assume they're sorting it out with the factory now, and perhaps we'll see a debugged version of the strobe in a few months.

I wouldn't call them dishonest outright; probably closer to misinformed. It's likely that they contracted some mainland China electronics manufacturer to rip off the Z-240, and didn't properly check what they got. The strobe fires? Good, sell it! On the other hand, once we have notified them of the problem with the optical trigger circuit, they pulled the product from their websites almost immediately, which, to me, indicates that they're not out to deceive the customers by intentionally selling a substandard product. Let's wait and see how the situation develops. Have you contacted Meikon with your findings?

It is impossible to be refund by AliExpress. They closed the dispute without letting me give my evidence and Aliexpress continues to sell this strobe. Yes they are dishonest !
I'm going to try something with Meikon, but I do not believe it too much.

Note that Aliexpress doesn't sell things; it's a platform for various Chinese sellers to sell to overseas customers. While Meikon have pulled the ST-100 from their websites, I wouldn't expect second-tier resellers (Meikon Digital Technology Limited, the company behind Meikon and SeaFrogs brands, does not sell through Aliexpress) to react as quickly, nor would I rely on them to be knowledgeable about the products they sell. It's possible that this information will now filter up and down the supply chain, but it will certainly take some time to do so.

That's their B2B/wholesale site which does not sell directly to consumers, I'm guessing they don't update it as often. Note that it lists a bunch of other products that are not available from their consumer-facing websites either, like aluminium housings.

I noticed that you got your strobes from the same place I did. I sent a message to that supplier on September 12th, and yesterday, after waiting six days with no response, I contacted Aliexpress customer service, and left another message, linking your video. Overnight, I got two responses - one is that they can't view the video (I guess the Great Chinese Firewall blocks youtube?) and asking me to send it via email, the other requesting that I send the strobes in for repair, so the seller is not totally uncommunicative. I took the liberty of downloading a low-res version of your video and sending it to their @qq.com mailbox and further explained that this appears to be a design issue, which is unlikely to be repairable directly, so they should reach up the supply chain to figure out what can and should be done about it. Let's wait and see what shakes out.

While this situation is somewhat unpleasant, I see no reason to be hostile towards Meikon or their resellers - particularly in case of 2nd tier stores operating via Aliexpress, it isn't really reasonable to expect them to be experts on every single product that they sell; not at the margins that they charge anyway. It appears that they're willing to work towards a resolution, but considering the multiple parties involved, it will likely take a while.

Thank you for contacting us and we want to explain a few things to avoid confusion in the future.

We are not sure if you aware of this or not, but we are not the factory. Our company is just a seller of Meikon products and we have no affiliation with any China Mainland sellers, we don’t sell anywhere besides our website. So, we have nothing to do with other sellers that sell the product at Aliexpress or eBay or other online platforms. For this very reason we have a policy that we are only responsible for products which are purchased from our website.

About the strobe:

We are aware of this issue and even before, the older version of a strobe had some issues too. Because the strobe is so unreliable – we don’t sell it at our websites (www.meikon.com.hk , www.seafrogs.com.hk ).

Clearly you can see that some Chinese seller at Aliexpress doesn’t care what they sell and if it’s a good quality or not. The unspoken rule that pretty much everyone knows - when buying something from Aliexpress in 99% of the time the product you purchased comes without any sort of warranty and sellers there simply don’t care what happens next as long as they received the money. That is the price for purchasing products from sellers that are not specializing in one particular area and sell a million other things in their shop.

We would really suggest to avoid purchases from Aliexpress and in general if it looks too good to be true, its probably a scam of some sort.

The only suggestion about your particular situation we have is to make a claim to Aliexpress directly.

If you would like to contact the factory, please visit the factory website.

www.seafrogs.cc

We hope this information helps!

I managed to chat with AliExpress customer support.
Indeed the firewall prohibit Youtube.
I posted the video on Google Photo and gave the link.
It has promised to reopen the appeal within 3 to 5 days.

Hello friend,
We have sent the video to the factory, and waiting for their response too. we will ask them to send feedback ASAP.
Thank you so much!

As I have no immediate plans to take them underwater again - my dive trips are not that frequent, current plans being for a month-long trip to SEA around oct'19, with a couple short trips to Eilat/Aqaba/Sharm to tide me over until then - I can afford to be patient.

Heh, this is amusing - on meikon.com.hk and seafrogs.com.hk, the ST-100 has been replaced by Sea & Sea YS-03. If you think about it, they're remarkably similar - all those functions that don't work on ST-100 (in FO mode) are simply absent from YS-03, which only has a single on/off switch. YS-03 is somewhat smaller and lighter, but on the other hand, it lacks an aiming light and costs a bit more. With YS-03 being rated at GN=20, the actual light output is probably similar as well, although ST-100 probably cycles faster, as it doesn't come close to its full output in TTL mode - in my experience, it's always less than a second between pulses.

Since I had not seen anything on this item for a while, I sent the following note to SeaFrogs on November 3:

I purchased the ST-100 Pro Underwater strobe below a few months ago. While the strobe fires most of the time, none of the controls appear to work as described. I noticed that this strobe is no longer shown on your website. Are you developing a fix for the strobe problems or developing a new strobe that actually works as described? Are you providing rebates or compensation or replacement strobes for this product?

On November 6 I received the following response:

Please send the strobe back to us and we will replace it with a new one.

Like Wolf Ell, I didn't see any reason to spend the money to send the strobe back if the issues have not been addressed. Anyone else have any updates on this strobe?

I bought 2 of the strobes from Cameramans store on Aliexpress. One is still working but one failed after a short period. After lots of messages they sent me a replacement strobe after I mailed back the defective one at my expense ($60). The new worked for about 1 month and now does not fire. The LED focus works and the red/green charge light works but no strobe fire. i sent about a dozen messages to Cameramans store but none have been answered. Definitely a waste of money and time